For the second time in less than a month, the Obama administration on Friday took an action that all but shuts the door on drilling in the Atlantic Ocean, denying six permits to companies seeking to use seismic cannons to search for oil under the ocean floor.

The president’s decision stymies the oil industry’s hopes to drill off the coast between Delaware and Florida. It immediately drew scorn from the industry’s political supporters and lobbyists, though it was applauded by conservationists worried about the permanence of the president’s considerable environmental legacy once Donald Trump takes office.

Last year before Christmas, Obama used a little-known law that gives presidents the discretion to protect public land and banned hundreds of millions of acres of federally owned territories in the Arctic and Atlantic oceans from new offshore oil and gas drilling. His latest action appeared to be made with an eye on the president-elect, who promised in his campaign to “open onshore and offshore leasing on federal lands” and to “unleash America’s $50 trillion in untapped shale, oil, and natural gas reserves, plus hundreds of years in clean coal reserves.”

Friday’s announcement by the Bureau of Ocean Energy Management, a division of the Interior Department, said the decision was based on several factors, including an earlier moratorium that closed the Atlantic to leases that allow companies to explore and drill for oil until 2022. There also were concerns that seismic testing could harm marine animals, particularly dolphins, porpoises and whales that use sonar to communicate and hunt for food, according to the agency.

“In the present circumstances and guided by an abundance of caution, we believe that the value of obtaining the geophysical and geological information from new air-gun seismic surveys in the Atlantic does not outweigh the potential risks of those surveys’ acoustic pulse impacts on marine life,” director Abigail Ross Hopper said in a statement. “Since federal waters in the Mid- and South Atlantic have been removed from leasing consideration for the next five years, there is no immediate need for these surveys.”

The bureau asserted in the statement that any seismic tests conducted in the coming months “may become outdated if leasing is far in the future.” It added that the seismic technology might improve in the next few years to where it would have less impact on marine animals. The statement did not identify the oil and natural gas companies that were denied permits.

Eric Wohlschlegel, a spokesman for the American Petroleum Institute, which represents the oil and gas industry, blasted the announcement, calling it “a politically driven decision that flies in the face of the best available science.” Wohlschlegel said bureau officials previously have called seismic surveys a safe and scientifically proven way to find energy sources.

Smoke billows from controlled oil burns near the site of the 2010 Deepwater Horizon oil spill in the Gulf of Mexico . (Derick E. Hingle/Bloomberg)

“We are hopeful the incoming administration will reverse this shortsighted course and base its decisions on facts so that we can have a forward-looking energy policy to help keep energy affordable for American consumers and business, create jobs and strengthen our national security,” Wohlschlegel said.

During his campaign, Trump indicated a willingness to reverse the current administration’s course, “rescind all job-destroying Obama executive actions” and “reduce and eliminate all barriers to responsible energy production.”

Seismic surveys are conducted to map the ocean floor and help determine its geography, rock distribution and layers of earth. They are done by ship-towed air guns that emit an acoustic pulse of energy across expansive areas of the sea floor for long durations. In 2012, when the Obama administration considered allowing the testing as part of an effort to increase domestic oil production, conservationists responded angrily.

Michael Jasny, a senior analyst for the Natural Resources Defense Council, called such testing “a death sentence” for acoustic animals that had evolved over a million years to use sonar. A representative for the Sierra Club’s Virginia chapter, which fears oil contamination along state beaches, asked: “Why explore when we don’t want drilling in the first place?”

A senior attorney for the Southern Environmental Law Center said the decision indicates that the government “is listening to coastal residents” who oppose testing and drilling. “The seismic blasts have been known to travel more than a thousand miles through the ocean, potentially disorienting, hurting… or even killing nearby marine life,” Sierra Weaver said. Weaver also raised economic concerns, saying that “seismic blasts also drive away fish, drastically cutting commercial fishing production.”